The Clinical Core operates as the unit of the Oregon Alzheimer's Disease Center (OADC) with responsibility for identification, recruitment, characterization, and follow-up of populations of well-characterized subjects for clinical dementia research. In order to fulfill this mission, the Clinical Core completes systematic assessments resulting in standardized diagnoses of the research cohort which are then entered into the relational database of the OADC. Many types of data are collected in order to be responsive to current and anticipated needs of the research community: clinical histories, neurological examinations, MRI brain images, neuropsychological and behavioral assessments, and laboratory data. The Clinical Core works closely with the other Cores of the Center to ensure tissue donations (Neuropathology Core), characterization of genetic- associations (Genetics Cores) and smooth transfer, entry, storage and eventual retrieval for analysis of the data no subject is lost to follow-up. Several groups form a particular focus of the Clinical Core. These include Alzheimer's disease patients, Parkinson's disease patients with dementia, and elderly control subjects. The latter subjects are derived from a unique population of optimally healthy elderly (most age 85 years or older) who because of their age are at high risk to develop dementia, and a group of elderly control subjects of average health all consenting to brain donation. The Clinical Core also enhances the research aims of the OADC through it's Satellite Programs comprised of 3 main components: 1) an African American minorities program in Northeast Portland enrolling an estimated 20% sample of all elderly African Americans with dementia in the Portland metropolitan area, as well as control subjects; 2) a Native American program enrolling all elders over age 60 residing on the Warm Springs Reservation in central Oregon; and 3) supporting development of a new rural Oregon population-based seniors study of very elderly in the remote Klamath Basin region of Oregon.